PROJECT ABSTRACT: A research infrastructure in geriatric emergency care is needed to develop and test best practices in the ED setting that address the medical, health, and psychosocial needs of older patients. Despite evolution of interdisciplinary geriatric emergency department (GED) guidelines and the rapid growth and spread of self- declared GEDs, there is limited evidence of what better quality geriatric emergency care consists of and even less is known about the impact such care may have on patient outcomes. Thus, there is an imperative to advance interdisciplinary geriatric emergency medicine research. This proposal will leverage preliminary work from an early learning collaborative of 9 hospitals and health systems implementing geriatric emergency medicine initiatives and an early platform clinical data registry to create an interdisciplinary research infrastructure. The goal of this proposal is to launch the Geriatric Emergency care Applied Research (GEAR) Network and facilitate the framing and building of a research infrastructure supporting interdisciplinary aging studies focused on geriatric emergency medicine. Specifically, this network will: 1. establish research priorities and standardized data approaches and measures for common geriatric emergency care syndromes, 2. build a validated data bank to support opportunities to conduct geriatric emergency care research, and 3. facilitate future multicenter proposals and applications for pragmatic trials, dissemination and implementation studies, and other interdisciplinary projects that will further the advancement of best practices in geriatric emergency care. During the first framing phase (2-year R21) an interdisciplinary research task force will be convened of geriatricians, emergency physicians, nurses, social workers, representatives of the 9 hospital collaborative, data informatics experts, methodologists, pragmatic clinical trials experts, and dissemination and implementation scientists. Following a structured research-to-practice consensus building format, this task force will propose priorities and standardized measures for common geriatric syndromes and conditions encountered in the ED. Four cores will be organized in research, measurement, data and informatics and dissemination and implementation to support the 3-year R33 phase. During the second building phase, a data bank will be created from measures proposed by the task force. A multicenter evaluation will standardize, validate and test these measures for feasibility of implementation. In the latter phase of the R33, there will be an open call for 1-year pilot proposals. Pilot funding will preferentially support nascent investigators in geriatric emergency medicine that propose interdisciplinary collaborations and use data driven approaches from the GEAR infrastructure. The generation of preliminary data from these studies will further develop and build future opportunities for multicenter, interdisciplinary aging study grant proposals.